Bug#846520: pcl: enable parallel builds on 32 bit arches

[Emilio Pozuelo Monfort]

On 01/12/16 23:25, Jochen Sprickerhof wrote:
> Hi Emilio,
> 
> * Emilio Pozuelo Monfort <pochu at debian.org> [2016-12-01 22:24]:
>> Why was this disabled? Do the builds run out of memory often? It'd be good
>> to re-enable this, the speedup is huge and it would avoid taking one buildd
>> for a day and a half on some architectures.
> 
> Exactly because it was running out of memory. Quoting from the buildd:
> 
> | cc1plus: out of memory allocating 903468 bytes after a total of 19152896 bytes
> 
> I asked in #debian-buildd back then and the consensus was to remove the
> --parallel. Is there any reason to revert this now?

We have more powerful buildds, at least in some architectures. Not sure about
RAM/swap. Also there was one bad build back then, but several good builds. I'm
not sure if this is such an issue, but I think it's worth re-trying. Doesn't
need to happen right now just for the sake of it, it can be uploaded when there
are other worthwhile changes.

If parallel support is re-enabled and some builds fail, we can evaluate whether
it's best to disable parallel support on specific architectures, blacklist pcl
in specific buildds, lower the parallelism without disabling it entirely, or
disabling it altogether in 32-bits architectures again.

Cc'ing debian-wb-team@ to see if anybody disagrees.

Thanks,
Emilio